Electric contact device.



A. A. KENTr V ELECTRIC CONTACT DEVICE- APPLICATION FILED JUNE 30. I916 Patented Nov. 13, 1917.

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r W J ATT/ORNEY WITNESS 'A. A. KENT.

ELECTRIC CONTACT DEVICE.

APPLICATION FILED JUNE 30. 1916.

1 ,246 ,8 1 8. Patented Nov. 13, 1917.

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I f g; m /36 INVENTOR -ATTORNEY UNITED STATES PATENT OFFICE.

ABTHUBATWATER KENT, OF BOSEION'L'PENNSYLVANIA.

ELECTRIC CONTACT DEVICE.

1,246,818. Specification of Letters mum. t t 7 Division in part of application Serial 1T0. 707,725, filed July Ii, 1812. This application filed June 80, 1918.

Serial No.

To all whom it may concern:

Be it known that I, ARTHUR ATWATER KENT, a citizen of the United States, and a resident of Rosemont, county of Montgomery, State ofPennsylvania, have invented certain new and useful Improvements in Electric Contact Devices, of which the following is a full, clear, and exact disclosure.

My invention relates to contact makers and more particularly to those devices which are operated to mechanically make and break the primary electrical circuit of a sparking system of an internal combustion engine.

Among the objects of my invention are the providing of a contact device with a condenser therein bridging the spark gap of the contact points of the contact device, and to so construct, ariange and dispose the parts of the contact maker as to adapt it to support and contain the condenser therein in such a manner that the condenser will be connected to the contact points without wiring; to make the device simple in construction, easily assembled and of relatively few parts, all of which are readily accessible for adjustment or replacement.

Further objects of my invention are to provide means whereby the rapidly operated spring actuated-parts will not rebound from the stops against which they strike in returning to their normal position; to reduce the noise due to the striking of the rapidly reciprocating parts of the contact maker, and to make the device as nearly noiseless as possible.

Other objects of my invention will appear in the specification and claims below.

In the drawings forming a part of this specification in which the same reference characters are used throughout the various views to designate the same parts, Figure 1 is a top plan view of my improved contact maker; Fig. 2 is a sectional view thereof taken on the line 22 of Fig. 1; Fig. 3 is a longitudinal sectional view of the holder for the s'rationary contact point; Fig. 4 is a sectional'view taken on the line 4-4 of diagrammatically illustrated as contained between said members and indicating the manner in which the termlnals of the con- .denser are electrically attached to the two parts ofthe contactmaker; Fig. 7 is a sectlonal view on a somewhat enlarged scale of the stop against which the lifter of the contact maker normally rests and to which it rapidly returns in making and breaking the c1rcu1t; and Fig. 8 is a sectional view on an enlarged scale of the stop which cooperates with the intermediate member of the mechanism for actuating the movable contact Joint.

My improved contact device comprises a substantially circular base 1 preferably of cast iron, provided with suitable ln s 1'-1-1 by means of which it may e mounted on and secured to any suitable support. Within the said base 1 is journaled a shaft 2, driven in any suitable manner from the main shaft of an internalv combustion engine, and arranged to turn preferably at the same speed as the shaft of the engine. The shaft 2 is provided with ratchet teeth 3, adapted to cooperate with and actuate a lifter 4, which is provided with a detent5 at one end thereof adapted to engage successively the ratchet teeth 3. The end of the lifter 4, which is provided with a detent 5, rests 'at all times on the shaft 2, and the other end of the lifter 4 is slidingly supported in a groove 6 of a stud 6. The lifter 4 is held at all times so that its respective ends bear continuously on the shaft 2 and stud 6, by a coiled spring 7, provided at one end with a hook 8, passing through an opening 9 in the lifter 4 and having its other end secured to the stud 10 projecting from the base 1. The spring 7 is disposed at such an angle to the lifter 4 as to hold the said lifter 4 on the shaft 2 and stud 6, respectively, and as to tend to draw the lifter 4 toward, and hold its foot 11 against, a stop 12 on the base 1.

The end of the lifter 4 having the detent 5 is provided with a sharp edge 13 adapted to cooperate with a sharp edge 14 on the intermediate member 15, which is pivoted on a pin or stud 16 secured to the base 1.

The intermediate member 15 is normall held yieldingly pressed against a sto 1 similar in construction to the sto 12, y a movable contact member 18, whic conslsts of a spring 19 rigidly secured at one end to a post or projection 20, by a screw 21, and a re atively stiif hook-like member 22 firmly attached to the said spring 19. The tension of the spring 19 is such as to tend-to hold 1 pin or stud 23 projectin the back or closed side of the hook-like member 22 pressed against the conical'end of the from the intermediate member 15, an consequently to hold the intermediate member 15 normally against its stop 17.

The spring 19 is preferably riveted between the stiff hook-like member 22 andthe fiat leaf spring 24, the free end of which is pressed against the under side of the free end of the hooked member 22.

The spring 24 is provided with a tungsten contact point 25 near the free end thereof. The spring 19 and'the parts carried thereby will .for convenience be referred to as the movable contact member of the contact device and the tungsten point 25 will be termed for convenience the point. All the parts above described are preferably made of metal and are attached or connected to the metallic base 1, and, therefore, they are electrically connected together. In other words, all the arts above described are electrically groun ed to the base 1.

Secured to the base 1, but electrically insulated therefrom, is the stationary contact member 26. This member 26 is also preferably made of cast iron and is secured to the base 1 by two screws 2727, the threaded ends of which screw into the tapped holes 2828 in the base 1. The said screws 2727, respectively pass through and are surrounded by a cylindrical bushing 29 of insulating material, said bushings 29 substantially fitting within holes 30 -30 in the movable contact stationary contact member 26. The lower. or inner ends of said bushings 29 fit respectively into washers 31 of insulating material which are operative to electrically insulate the base 1 from the stationary contact member 26. The upper or outer ends of the bushing 29 respectively pass through and fit within washers 32, also of insulating material, and between each head of said screws 27 and the washers 32, respectively, is a metallic washer 33 preferably of smaller outside diameter than the Washers 32.

The metallic stationary contact member 26 'is thus rigidly secured to the metallic base 1, but is preferably electrically insulated therefrom.

The stationary contact member 26 is provided with an arm 34 carryingnear its free end a plate 35 secured to the arm 34 by a screw 36 which passes through a slot 37 extendin longitudinally of said plate 35. Said p ate 35 is-preferably provided with an off-set portion 38 to which is securely attached the stationary contact point 39, preferably of tungsten. The opposite end of the plate 35 may be provided with a knob or handle 40, so that by loosening the screw 36 and slipping the plate longitudinally, by the knob 40, the distance between the contact points 25 and 39 may bereadily adjust, ed and may be maintained in such adjusted position by tightening or setting the screw 36.

The stationary contact member 26 is also provided with a recess 41 preferably rectangular in shape and adapted to register, when the member 26 is secured to the base 1 in the manner above described, with a similarly disposed and similarly shaped recess 42 in the base 1. The recesses 41 and 42, to-

ether, form a pocket adapted to hold a conenser 43.

\ The two terminals 44 and 45 of: the condenser 43 are preferably flexible co perstrips andare bentback from the end 0 the condenser from the end of which they project over opposite sides of the body of the condenser 43, so that when the condenser 43 is placed in said pocket one terminal, 44, bears against the top of the recess 41 in the stationary contact member 26 and the other terminal 45 bears against the bottom walls of the recess 42 of the base 1.

Thus, when the condenser is placed in the recess 42 and the contact member 26 is placed over it and is secured to the base 1, one terminal, 45, of the condenser is in electrical contact or engagement with the base 1 and through the base with the contact point 25, and the other terminal 44 is in electrical engagement with the stationary contact member 26, and through, the member 26 with the contact point 39, and that without any binding screws, clamps, soldered connections, or any other of the usual electrical uniting means commonly employed for the purpose. The simplicity of construction and the'low cost of manufacturing and assembling these parts will be apparent from the foregoing description.

The stationary contact member 26 is provided with a bindin screw or post 46, to which one wire po e or terminal of a primary electric circuit of an igniting system may be attached by clamping the same between the said member 26 and a brass or copper washer 47 surroundin said screw 46, and the base 1 is prefera 1y provided with a relatively large hole or opening 48 in alinement with the screw 46 to insure against any accidental electrical contact bemanner the condenser 43 bridges the gap be? I the lifter 4 is normally held by the spring.

tween the contact p'oints25 and 39.

The stops 12 and 17 are constructed to prevent a rebound of the lifter 4 and theintermediate member 15 respectively therefrom as they are rapidly returned against them by their respective springs 7 and 19 and to reduce the noise incidentv to the blow produced by the striking of the said movable members against said stops.

The stop 12, against which the foot11 of 7, is particularly illustrated in Fig. 7, an

comprises a stud 51 of flexible or resilient wire of relatively small diameter, provided with a relatively large heavy head 52 rigidly secured thereto, the lower end of the stud 51 being rigidly secured to the base '1, as, for instance, by screw threads 53, tightly fitting within a tapped hole 54 in the base 1. Mounted upon the stud 51, and fitting it rather snugly, is a relatively heavy roller 55, which is rotatable on the stud 51 and is of a slightly larger diameter than the head 52. The foot 11 of the lifter 4 normally rests against the roller 55 and when removed therefrom returns very rapidly under the influence of the spring 7, striking a sharp .blow on the relatively heavy roller 55.

The stop 17 also consists of a similar stud 56 of resilient wire and is similarly provided with a relatively heavy head 57 rigidly secured thereto, the lower end of the stud '56 being provided with screw 1 threads 58 tightly fitted within the tapped hole 59. The stud 56 is provided with a similar roller .60 of a slightly larger diameter than the head 57 which rather snugly surrounds the stud 56, but which is rotatable thereon. The

free end of the intermediate member 15 is held normally against the roller 60 by the tension of spring 19, forcing the back of the hook-like member 22 against it, and when the member 15 is lifted out of engagement with the' roller 60 and is then quickly returned by the spring 19 to its normal position against the roller 60, it strikes the roller 60 with considerable force.

The operation of the device is as follows: As the shaft 2 is rotated by the engine in the direction of the arrow 61, the detent 5 of the lifter 4 is engaged by a ratchet tooth 3 and is carried by the ratchet in the direction of the arrow 62 until the sharp edge 13. has passed beyond and under but out of contact with the sharp edge of the intermediate member 15. Beyond this point, the tooth 3 slips from its'engagement-with the detent 5, and the spring 7 rapidly returns the lifter 4 to its normal position as shown in Fig. 1,-

lowing thecontour of the" shaft 2 between the member 15 free tobe instantly returne \oits stop 17 under the influence of the sprmg19. This action also instantly causes a separationof the contact points 25 and 39. In returning to its original position, the intermediate member 15 strikes a sharp blow on and against the roller 60. f

If the. shaft 2 be revolved at the same speed as the shaft of the engine, the shaft 2 should be provided with as many ratchet teeth as there are cylinders to be exploded during a revolution of the engine shaft. The distribution of the spark to the various clylmders is controlledby a distributer (not s own) such. as is ordinarily used in connection' with contact devices of this'character.

- In this manner the contact points 25 and 39 are almost instantly closed andseparated again and a very strong spark may be thereby induced. The jumpingof the spark between the contact points 25 and 39 isprevented, however, by the condenser 43 which, as above set forth, has its terminals inelectrical engagement with the contact points 25 and 39, respectively.

0 I have found that when the rapidly reciprocating parts, such as the lifter. 4 and the intermediate member 15, are arranged so that in their return movements they strike against relatively resilient stems, such as the studs 48 or 53, at a point between the heavy heads 52 or 57 and the point of support of sald studs, the said parts do not appreciably rebound. .The shock or blow mits of an accurate and close adjustment of the contact points 25 and 39. There being no rebound of the lifter or intermediate member, a very accurate timin of their action may be made and the 'evice will make and break the circuit most regularly and accurately even when operating at exceedingly high speeds.

It will be seen that the base 1 and the upper contact member 26 constitute in fact twe fcotiperating plates or members which are' ifelectrically insulated from each other and between the condenser 43 is held or clamped in any suitable manner so as to bridge the gap between the contact points. One of said members is electrically united with or connected to the movable contact point and the other of said members is in similar electrical engagement with the stationary contact point.

The movable contact point 25 is in electrical contact with the base or member 1 through the post or stud 20 and is insulated from the base at every other point, the pin or stud 15 being preferably of insulating material.

For such details of the contact maker as are shown and claimed herein, and are shown and not claimed, in a prior application filed by me July 5, 1912, Serial No. 707 ,725, this application is to be considered as a continuing application.

Having thus described my invention, what I claim and desire to protect by Letters Patent of the United States is:

1. In a contact device, the combination of a metallic base, a movable contact point electrically connected to said base, a stationary contact point, a metallic member on which said stationary contact point is mounted, means to rigidlv secure said member to said base spaced a art and electrically insulated from said ase, and a condenser clamped between said base and said member and having its terminals in electrical engagement with said base and member respectively.

2. In a contact device, the combination. of a metallic base, a movable contact point electrically connected to said base, a stationary contact point, a metallic member on which said stationary contact point is mounted, means to rigidly secure said member to said base spaced apart and electrically insulated from said base, and a condenser held by and between said base and said member, the two terminals of said condenser lying on opposite sides of the body of said condenser and each-lying between said condenser body and the base, and between said condenser body and said member respectively.

3. In a contact device, the combination of a metallic base provided with a recess, a movable member electrically connected to said base, a metallic stationary contact member mounted upon said base and electrically insulated therefrom and provided with a recess complemental to and in registration or alinement with the said recess in said base, means to secure said stationary contact member rigidly to said base but electrically insulated therefrom, and a condenser tightly fitting within said recess and in tight engagement with the said base and said stationary contact member.

i. In a contact device, the combination of a metallic base provided with a recess, a movable member electrically connected to said base, a metallic stationary contact member mounted u on said base and electricall insulated t erefrom and provided with a recess complemental to and in registration or alinement with the said recess in said base, means to secure said stationary contact member ri idly to said base but electrically insulated t erefrom, and a condenser tightly fitting within said recess and in tight engagement-with the said base and said stationary contact member, the two terminals of said condenser being in electrical engagement respectively with said base and said stationary contact member.

5. In a contact device, the combination of a metallic base provided with a recess, a movable member connected to said, base, a metallic stationary contact member inounted upon said base and electrically insulated therefrom and provided with a recess complemental to and in registration or alinement with the said recess in said base, means to secure said stationary contact member rigidly to said base but electrically insulated therefrom, and a condenser tightly fitting within said recessand in tight engagement with the said base and said stationary contact member, the two terminals of said condenser being between the body of said condenser and said base and stationary contact member respectively, and in electrical engagement therewith.

6. In a contact device, the combination of a base, a lifter, a stop, a spring normally tending to hold said lifter against said stop, and means to advance said lifter away from said stop against the tension of said spring and to then release said lifter whereby said lifter is quickly returned by said spring to its normal position against said stop, said stop comprising a resilient stud rigidly mounted in said base, a relatively heavy head rigidly secured to the free end of said stud, and a heavy roller snugly fitting around said stud between said base and said head against which said lifter strikes in returning to its said normal position.

. 7. In a contact device, the combination of a base, a lifter, a member pivoted on said base, a stop against which said member is normally held, and resilient means to normally hold said member against said stop, said member being intermittently moved by said lifter to close an electric circuit, said stop comprising a resilient stud rigidly mounted in said base, a relatively heavy head rigidly secured to the free end of said stud, a relatively heavy roller fitting around said stud between said base and said head against which said member strikes in returning to its normal position.

8. In a contact device, the combination of a movable member, a stop, a spring for normally holding said member against said stop, means to move said member away Y from said stop and to then release it whereby said member is sharply drawn by said spring against said'stop, said stop comprising a resllient rod or stud rigidly supported at one end, and a relatively heavy head on the free end of said rod or stud, the point of impact of sald member against said rod or stud being between said head and the point of support of said rod or stud.

9. In a contact device, the combination of a reciprocatory lifter, means to advance said lifter in one direction and to then release it, a spring to return said lifter to its normal posltion, a re-bound absorbing stop against which said lifter strikes at the end of its return movement, an oscillatory intermediate member momentarily engaged by said lifter on its said return movement, a re-bound absorbing stop against which said intermediate member is normally held and from engagement with which it is moved by said lifter on its said return movement, and a movable contact member yieldingly pressing against said intermediate member and tending to hold said intermediate memberagainst its stop and operative to return said intermediate member to its stop after said lifter has passed from engagement therewith.

10; In a contact device, the combination of a reciprocatory lifter, means to advance said lifter in one direction and to then release it, a spring to return said lifter to its normal position, an oscillatory intermediate member, and a contact point operated by the movement of said intermediate member, said lifter being provided with a sharp edge arranged to momentarily engage a cooperative sharp edge on said intermediate member as said lifter strikes said intermediate member on its return movement.

11. In a contact device, the combination of a' metallic base, a movable contact point electrically grounded to said base, a metallic stationary contact point supporting member rigidly secured to said base and electrically insulated therefrom, and a stationary contact point secured to said member, said contact point comprising a plate havin a longitudinal slot therein and provide with a down-turned end, a contact point rigidly secured to said down-turned end, a screw passing through said slot and into said member for securing said stationary contact point to said supporting member in different adjusted positions.

12. In a contact device, the combination of a metallic member, a movable contact point electrically connected therewith, a stationary contact point, a second metallic member on which said stationary contact point is mounted and to which said station ary point is electrically connected, means to rigidly secure said members rigidly together but electrically insulated from each other and a condenser held between said members and having its terminals in electrical engagement with each of said members respectively.

13. In a contact device, the combination of a base, a lifter, a stop, a spring normally tending to hold said lifter against said stop, and means to advance said lifter away from said stop against the tension of said spring and to then release said lifter, whereby said lifter is quickly returned by said spring to its normal position against saidstop, said stop comprising a resilient stud rigidly mounted in said base and a relatively heavy head rigidly secured to the free end of said stud, the point of impact of said lifter against said stop being between said head and said base.

14. In a contact device, the combination of a base, .a lifter, a rebound preventing stop, a spring normally tending to hold said lifter against said stop, and means to advance said lifter away from said stop against the tension of said spring and to then release said lifter, whereby said lifter is quickly returned by said spring to its normal position against said stop and said lifter does not substantially 're-bound from said stop.

15. In a contact device, the combination of a base, a lifter, a member pivoted on said lifter, a rebound preventing stop against which said member is normally held, re-. silient means normally holding said member against said stop, said member being intermittently moved away from said stop by said lifter and returned against said stop by said resilient means, whereby any re-bound of said member from said stop is prevented.

In witness whereof, I have hereunto set my hand this twenty-eighth day of June, 1916.

ARTHUR ATWATER KENT. 

